This section introduces aspects that may help facilitate a better understanding of the disclosure. Accordingly, these statements are to be read in this light and are not to be understood as admissions about what is or is not prior art.
The field of non-contact thermal imaging is associated with a variety of applications, e.g., measuring thermal characteristics of an electronic device under test. Thermal imaging using thermoreflectance has received attention in recent years. Thermoreflectance-based imaging is dependent on the measurement of the relative change in the sample's surface reflectivity as a function of temperature. As the temperature of a sample changes, the refractive index, and therefore, the reflectivity also changes. The change in reflectivity is dependent on the Thermoreflectance Coefficient, a basic material property that is a function of the illumination wavelength, the sample material and material surface characteristics, and the ambient temperature. U.S. Pat. No. 7,173,245 to Shakouri et al., incorporated by reference in its entirety into the present disclosure, describes such systems and methods.
In one method, an optical signal can be used to illuminate an electromagnetically radiating device that is energized. However, electromagnetic emission from the device under test while in the energized state can play havoc with thermoreflectance measurements.
There is, therefore an unmet need for a novel method and system that can perform thermoreflectance measurements while not affected by the stray electromagnetic emission of a device under test when the device is energized.